Encoded data recording apparatus and mobile terminal

ABSTRACT

In a mobile terminal provided with an encoded data recording function, there is assumed a condition in which a picture frame transmitted from the terminal of a communication partner is reproduced by means of decoding processing and is displayed on a LCD ( 34 ) during wireless TV phone communication. In this condition, when a user carries out a picture recording start operation, display picture data reproduced by means of decoding processing in the multimedia processing section ( 24 ) to be displayed on the LCD ( 34 ) are recorded in a main recording section ( 26 ).

TECHNICAL FIELD

The present invention relates to an encoded data recording apparatus anda mobile terminal used for example in a system handling encoded data.

BACKGROUND ART

In recent years, various information transmission systems such as abroadcasting system, a cable communication system and a mobilecommunication system have been put to practical use or planed, and as aresult thereof, various terminals have been developed.

For example, in a mobile communication system, mobile terminals such asmobile phones and PDAs (Personal Digital Assistants) are used. In thiskind of terminals, not only voice communication service, but alsovarious transmission services such as SMS (Short Message Service),electronic mail service and information distribution service usingwireless internet are available. When data including a large amount ofinformation such as motion picture data (or video data) are tried totransmit in the mobile communication system, they cannot be transmittedas they are because the transmission path band causes a bottleneck.

So, a compression/extension processing of video data is required intransmitting motion picture data wirelessly, and as one means ofrealizing the processing, the employment of a compression/extensionscheme called MPEG-4 (Moving Picture Experts Group-4) is beingdiscussed.

MPEG-4 represents data having correlations on the time axis such asvideo data with an initial frame and a difference frame. The initialframe is called I-Frame (Intra-coded Frame) and contains whole pictureinformation elements (absolute value information) of one pictureobtained by being compressed as a still picture. That is, the I-Framecomposes a picture frame having an independent meaning alone. Incontrast thereto, the difference frame is called P-Frame(Predictive-coded Frame) and mainly contains difference informationbetween the picture of the current frame and the picture of thepreceding frame. And, in the first timing after the start oftransmission an I-Frame is transmitted, and in the subsequent frametimings P-Frames are transmitted sequentially. By using MPEG-4, motionpicture data having an amount of information equivalent to several Mbpscan be transmitted with being compressed to several ten Kbps.

However, in a system employing such a compression/extension scheme, ifthe video recording button of the apparatus is pushed in receiving data,only difference frames can be recorded, and as a result thereof, itbecomes difficult to reproduce pictures effectively from the recordedvideo data.

So, in MPEG-4, an idea that the picture of each P-Frame is divided intoa large number of blocks and that absolute value information istransmitted in a part of blocks selected optionally from each P-Frame isemployed. The blocks in which the absolute value information istransmitted are called a macro-block respectively. By receiving aplurality of P-Frames and synthesizing the macro-blocks thereof, theapparatus can reproduce one picture data equivalent to picture data ofthe I-Frame.

Therefore, even if the picture recording button of the apparatus ispushed in receiving picture data, one picture data comprising absolutevalue information can be reproduced by receiving the same number ofP-Frames as the macro-blocks constituting one picture.

However, in a period from the start of video recording to the end ofreceiving the same number of P-Frames as the macro-blocks constitutingone picture, one picture data comprising absolute value informationcannot be reproduced. The above-described period lasts, for example,about 10 seconds. As a result thereof, users may fail to record videodata of desired scenes.

DISCLOSURE OF INVENTION

The present invention has an object of providing an encoded datarecording apparatus and a mobile terminal adapted to be able to recordhigh-quality data immediately after inputting a recording instructioneven if the recording is begun during data input or data reception.

In order to attain the above-described object, the encoded datarecording apparatus according to the present invention is an apparatusrecording encoded data composed of first data generated in the initialframe timing and a plurality of second data generated respectively inthe subsequent frame timings and comprises an encoded data input meansfor inputting the encoded data, a data reproduction processing means forreproducing the original data based on the first data and the seconddata of the encoded data inputted by the data input means, a recordingperiod specifying means for specifying the recording period of theencoded data from a user of the apparatus, and a recording controlmeans. And, when the recording period is specified by the recordingperiod specifying means in inputting the encoded data, the original datareproduced by the data reproduction processing means in the recordingperiod concerned is recorded in a recording medium by the recordingcontrol means.

Therefore, according to the present invention, when a recordinginstruction is inputted in receiving data, the original data reproducedby the data reproduction processing means will be recorded in therecording medium from this time on. Accordingly, high-quality originaldata equivalent to the first data can be recorded immediately after therecording instruction was inputted. Therefore, recorded data arereproduced, high-quality data can be reproduced from the time of havinginputted the recording instruction.

Moreover, the present invention is characterized in that the recordingcontrol means records original data reproduced by the data reproductionprocessing means in the recording medium in the first frame timing ofthe recording period and in that it records second data inputted by theencoded data input means in the recording medium in the frame timingsfollowing the first frame timing respectively.

Further, the present invention is characterized in that the recordingcontrol means re-encodes original data into first data and a pluralityof second data when it records reproduced original data in the recordingmedium. And, the present invention is also characterized in that thefirst data and the plurality of second data obtained by the re-encodingare recorded in the recording medium.

Due to such a composition, original data equivalent to first data arerecorded only at the starting time of recording, and in the subsequentrecording period inputted first data is recorded as it is. Accordingly,the amount of data recorded in the recording medium can be reducedsubstantially through the recording period in comparison to storingreproduced original data. Therefore, the storage capacity of a recordingmedium can be used more effectively, and it becomes possible to prolongthe recording time of data.

Further, in the present invention, the recording control meanstemporarily holds original data reproduced by the data reproductionprocessing means in the recording period till the input period of theencoded data ends. And, the present invention is also characterized inthat after the end of the input period of the encoded data thetemporarily held original data are re-encoded in first data and aplurality of second data and are recorded in the recording medium.

Due to such a composition, the amount of data recorded in the recordingmedium can be reduced substantially to prolong the data recording time.Moreover, it becomes possible to carry out the processing of re-encodingreproduced original data into first data and second data except in thereceiving period and the recording period of encoded data. As a resultthereof, no concentrated processing load can be realized in receivingand recording encoded data, thereby reducing the processing burden of aCPU or a DSP.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view showing the schematic organization of a mobilecommunication system that is a first embodiment of a data transmissionsystem in which an encoded data recording apparatus according to thepresent invention is used;

FIG. 2 is a view showing the layer structure of a multimediatransmission system according to MPEG-4;

FIG. 3A and FIG. 3B are views showing the appearance of a mobileterminal that is a first embodiment of the encoded data recordingapparatus according to the present invention respectively;

FIG. 4 is a block diagram showing the functional composition of themobile terminal shown in FIG. 3A and FIG. 3B;

FIG. 5 is a view for illustrating the operation of a video datacompression scheme using MPEG-4;

FIG. 6 is a view showing a first example of the recording operations ofvideo data carried out by means of the mobile terminal shown in FIG. 4;

FIG. 7 is a view showing a second example of the recording operations ofvideo data carried out by means of the mobile terminal shown in FIG. 4;

FIG. 8 is a block diagram showing the functional organization of amobile terminal that is a second embodiment of the encoded datarecording apparatus according to the present invention;

FIG. 9 is a view showing the recording operations of picture datacarried out by means of the mobile terminal shown in FIG. 8;

FIG. 10 is a block diagram showing the functional organization of amobile terminal that is a third embodiment of the encoded data recordingapparatus according to the present invention; and

FIG. 11 is a view showing the recording operations of video data carriedout by means of the mobile terminal shown in FIG. 10.

BEST MODE FOR CARRYING OUT OF THE INVENTION

Now, several embodiments of the encoded data recording apparatusaccording to the present invention will be described with reference tothe drawings.

First Embodiment

In a first embodiment of the present invention, the present invention isapplied to a mobile terminal having an encoded data recording function.It is assumed that a picture frame transmitted from the terminal of acommunication partner side is decoded and displayed on a display sectionduring communication by means of wireless TV phones using MPEG-4. When auser carries out a recording start operation in this condition, decodedvideo data generated to be displayed on the display section are recordedsequentially in a main recording section till a video recording endoperation is carried out.

FIG. 1 is a schematic organization view of a mobile communication systemaccording to this first embodiment. In the same figure, a plurality ofbase stations BS1, BS2, . . . are distributed in a service area coveredby the system. These base stations BS1, BS2, . . . are connectedrespectively to a network NW. Mobile terminals MS1, MS2, . . . areconnected respectively to the nearest base stations BS1, BS2, . . . overradio channels and are further connected from these base stations BS1,BS2, . . . to the network NW. In the network NW, corresponding to thecalling requests of the mobile terminals MS1, MS2, . . . , a processingfor connecting between the mobile terminals MS1 and MS2 by means ofswitching is carried out. And, once a communication link has beenestablished between the mobile terminals MS1 and MS2 by means of theswitching connection processing, TV phone communication is subsequentlypermitted between these mobile terminals MS1 and MS2.

Moreover, as the above-described wireless access scheme, a W-CDMA(Wideband-Code Division Multiple Access) scheme is, for example, used.As other wireless access schemes, a cdma 2000 scheme, a FDMA (FrequencyDivision Multiple Access) scheme, a TDMA (Time Division Multiple Access)scheme, or a Narrowband CDMA scheme may be also employed.

FIG. 2 is a view showing the scheme of wireless TV phone communicationin the mobile communication system by means of multiplexing transmissionof motion picture data (or video data), speech data and computer databetween the mobile terminals MS1 and MS2.

The mobile terminals MS1 and MS2 are connected to each other by means ofa physical layer (concretely, a mobile switching network NW). And dataare transmitted in a packet called MUX-PDU as a unit. In the MUX-PDU, asshown in FIG. 2, a flag and a header are disposed on the head end, andbehind them the video data, speech data and computer data are disposedalternately. Control information representing the contents of theMUX-PDU is inserted into the header.

Above the physical layer an AL/MUX layer (concretely, a multipleseparation section) is disposed. In this AL/MUX layer the MUX-PDU isgenerated. Moreover, above the AL/MUX layer a higher-grade layer isdisposed. In this layer a video channel, an audio channel and a controldata channel are connected. The higher-grade layer is realized by meansof a multimedia processing section described later, a speech codecsection and a data communication section.

Video data are bundled and transmitted via the video channel. A MPEG-4stream is embedded into the video channel. In this MPEG-4 stream, asshown in FIG. 4 described later, an I-Frame containing all the pictureelements of one picture is transmitted first. In the subsequent frametimings, P-Frames containing mainly difference data between a currentframe and the preceding frame are transmitted sequentially.

Now, the mobile terminals MS1, MS2, . . . are composed respectively asfollows. FIGS. 3A and 3B show the appearance thereof, and FIG. 3A is afront view and FIG. 3B is a side view.

These mobile terminals MS1 and MS2 have a wireless TV phonecommunication function. On the front panel of the casing there aremounted a microphone 31, a speaker 32, a liquid crystal display (LCD) 34and a key input section 35. And a telescopic antenna 11 and a camera 33are provided on the top of the casing. This camera 33 employs a solidpickup device such as a CMOS or CCD and can pick up still pictures ormotion pictures. Further, on the rear of the casing there is provided abattery mounting section. A battery pack composing a power sourcesection 4 is detachably mounted in this mounting section.

Now, the circuit of the mobile terminals MS1, MS2, . . . is composedrespectively as follows. FIG. 4 is a block diagram showing thecomposition.

That is, the mobile terminals MS1, MS2, . . . are composed of a radiosection 1, a base band section 2, an input/output section 3 and a powersource section 4 respectively.

Radio frequency signals coming from the base stations BS1, BS2, . . .over radio channels for the mobile communication system are received atthe antenna 11 and are subsequently inputted into a receiving circuit(RX) 13 via a duplexer (DUP) 12. The receiving circuit 13 is providedwith a low-noise amplifier, a frequency converter and a demodulator.

And, after being amplified by means of the low-noise amplifier, theradio frequency signals are mixed with received local oscillatingsignals in the frequency converter and are down-converted into receivedintermediate frequency signals or received base band signals, and theoutput signals are demodulated digitally by means of the demodulator.Demodulation is carried out in steps of a primary demodulation and asecondary demodulation. As a primary demodulation scheme a spectrumreversed diffusion using diffusion codes is employed, and as a secondarymodulation scheme an orthogonal demodulation scheme complying, forexample, with a QPSK (Quadriphase Phase Shift Keying) scheme isemployed. Further, the received local oscillating signals are generatedby means of a frequency synthesizer (SYN) 14 according to theinstruction of a main control section 21A.

Demodulated data outputted from the demodulator are inputted into a baseband section 2. The base band section 2 is provided with a main controlsection 21A, a multiple separation section 22, a voice code decodingsection (hereafter referred to as a voice codec) 23, a multimediaprocessing section 24, a temporary storage section 25, and a mainstorage section 26.

Among them, the temporary storage section 25 comprises, for example, aring buffer or FIFO (First-in First-out) memory, and according to theinstruction of the main control section 21A, it temporarily holdsdisplaying video data reproduced by the decoding processing in themultimedia processing section 24 and non-decoded received picture framesoutputted from the multiple separation section 22.

The main storage section 26 comprises, for example, a RAM (Random AccessMemory) or a EEPROM (Electrically Erasable and Programmable Read OnlyMemory), and according to the instruction of the main control section21A, it selectively holds decoded displaying video data and non-decodedreceived picture frames transferred from the temporary storage section25. Further, a portable flash EEPROM or the like detachable from mobileterminals can be used in this main storage section 26.

In the main control section 21A it is identified whether the demodulateddata are control information or multimedia information. As a result ofthis identification, if the demodulated data are multimedia information,they are inputted into the multiplex/demultiplex section 22 and aredivided here into received voice data and received video data. And thereceived speech data are inputted into the speech codec 23 and aredecoded here into speech signals. These decoded speech signals areamplified and outputted from the speaker 32 of the input/output section3.

On the other hand, the received video data are inputted into themultimedia processing section 24 and are decoded into picture data byframe. These video data are fed to the liquid crystal display (LCD) 34of input/output section 3 and are displayed.

Further, various kinds of information indicating the operationalconditions of this apparatus outputted form the main control section 21Aare also displayed on this LCD 34. This displayed information includes,for example, a telephone book, a detected receiving electric fieldintensity value and a remaining amount of power in batteries.

On the other hand, the transmitted speech signals of a terminal useroutputted from the microphone 31 of the input/output section 3 areinputted into the speech codec 23 of the base band section 2A. And,after having been processed into encoded speech data here, they areinputted into the multiplex/demultiplex section 22. Further, the videosignals of the face of a terminal user picked up by the camera (CAM) 33are inputted into the multimedia processing section 24 of the base bandsection 2A. And, after having been processed into encoded video datahere, they are inputted into the multiplex/demultiplex section 22.

In the multiplex/demultiplex section 22, the encoded speech data and theencoded video data are multiplexed according to a specified formatprescribed by ITU-T H.223 or the like. These multiplexed transmitteddata are inputted from the main control section 21A into thetransmitting circuit (TX) 15 of the radio section 1.

The transmitting circuit 15 is provided with a modulator, a frequencyconverter and a transmitted power amplifier. In the modulatortransmitted intermediate frequency signals are modulated digitally bythe transmitted data. Modulation is carried out in steps of a primarymodulation and a secondary modulation. As a primary modulation scheme,for example, a QPSK scheme is employed, and as a secondary modulationscheme there is employed a scheme in which signals after the primarymodulation are spectrum-diffused by means of diffusion codes. In thefrequency converter transmitted intermediate frequency signals modulatedby the modulator are mixed with transmitted local oscillating signalsand are up-converted into radio frequency signals with respect to thefrequency. Further, the transmitted local oscillating signals aregenerated by the frequency synthesizer 14 according to the instructionof the main control section 21A.

By means of the transmitted power amplifier the transmitted radiofrequency signals outputted from the frequency converter are amplifiedto a specified transmitted power level instructed by the main controlsection 21A. And they are fed to the antenna 11 via the duplexer 12 andare radiated from this antenna 11 towards base stations (not shown).

Further, in the power source section 4 there are provided a battery 41using lithium ion cells, a charging circuit (CHG) 42 for charging thisbattery 41, and a voltage generation circuit (PS) 43. The voltagegeneration circuit 43 comprises, for example, a DC/DC converter andgenerates a specified power source voltage Vcc based on the outputvoltage of the battery 41.

And in the input/output section there is provided an illuminator 36.This illuminator 36 is called, for example, a back light or anillumination and illuminates the LCD 34 and the key input section 35when a user operates keys or during communication.

The main control section 21A is provided with a microprocessor and aninternal memory comprising a ROM, a RAM and the like. Further, it isnewly provided with a displayed data recording control means 21 a inaddition to the usual control functions such as a connection controlfunction and communication control function of radio channels. Thesecontrol functions are realized by a control program contained in theROM.

This displayed data recording control means 21 a operates when a usercarries out a video recording start operation in the input/outputsection 3 during TV phone communication operation. And in a period fromthe time of this video recording start operation to the time of thevideo recording end operation, display video data decoded and reproducedin the multimedia processing section 24 are fed to the main storagesection 26 via the temporary storage section 25 and are storedsequentially so that they may be displayed on the LCD 34.

Moreover, the displayed data recording control means 21 a has also afunction of feeding display video data reproduced by means of a decodingprocessing at the time of the video recording start operation and eachreceived picture frame outputted from the multiple separation section 22in a period from the time of the video recording start operation to thetime of the video recording end operation to the main storage section 26via the temporary storage section 25 and of storing them sequentially.

Now, the recording operations of received video data in the mobileterminals MS1, MS2, . . . composed as described above will be described.

FIRST OPERATION EXAMPLE

Suppose that the mobile terminal MS1 and the mobile terminal MS2 shownin FIG. 1 start wireless TV phone communication using MPSG-4. Then, themobile terminal MS1 generates first an I-Frame in the initial frametiming based on the video data outputted from the camera 33 andtransmits this I-Frame. And in each frame timing after the second frame,a P-Frame mainly composed of difference information between the videodata of the current frame and the video data of the previous frame isgenerated, and this P-Frame is transmitted sequentially.

On the other hand, the mobile terminal MS2 receives first the I-Frametransmitted from the mobile terminal MS1, reproduces one-picture data inthe multimedia processing section 24 based on this I-Frame and displaysthese one-picture data on the LCD 34. And in the subsequent frametimings respectively the P-Frames transmitted from the mobile terminalMS1 are received sequentially. And by adding these P-Frames to thepicture data reproduced by means decoding processing respectively in theprevious frames, the one-picture data are reproduced, and theseone-picture data are displayed sequentially on the LCD 34.

FIG. 5 shows an operation example of the video data transmission schemeusing the MPEG-4 in the form of a model. In the same figure, supposethat video data shown in V1, V2, V3, . . . are outputted sequentiallyfrom the camera 33, for example, in the mobile terminal MS1 of thetransmitting side. Then the mobile terminal MS1 encodes first thepicture data V1 as still picture data and transmits the encoded picturedata obtained thereby as an I-Frame. On the other hand, the mobileterminal MS2 reproduces one-picture data V1, based on the receivedI-Frame and displays this on the LCD 34.

Next, each time the picture data V2, V3, . . . are outputted from thecamera 33, the mobile terminal MS1 detects the differences between thesepicture data V2, V3, . . . and the picture data V1, V2, . . . of theprevious frame respectively. And picture data mainly composed of thisdifference information are generated respectively and these picture dataare transmitted as a P-Frame. On the other hand, each time the P-Frameis received, the mobile terminal MS2 adds the difference informationthereof to the display picture data V1′, V2′, . . . produced in theprevious frames respectively, thereby reproducing one-picture data. Andthese reproduced display picture data V2′, V3′, . . . of one-picture aredisplayed sequentially on the LCD 34.

Now, suppose that a user has inputted a video recording startinstruction by operating the key input section 35, for example, in themobile terminal MS2 in a condition of carrying out the TV phonecommunication as described above.

Then the main control section 21A of the mobile communication terminalMS2 feeds display video data reproduced by means in the multimediaprocessing section 24 to the main storage section 26 via the temporarystorage section 25 at this time and stores them in the main storagesection 26. And the display data received subsequently till therecording end operation and reproduced in the multimedia processingsection 24 are respectively fed to the main storage section 26 via thetemporary storage section 15 sequentially and are stored in the mainstorage section 26. FIG. 6 shows how this recording operation is carriedout.

Therefore, even if the video recording start operation is carried out inreceiving a video data stream, display video data reproduced by thedecoding processing in the multimedia processing section 24 are recordedsequentially in the main storage section 26 from the time of theoperation. As a result thereof, when the display video data recorded inthe main storage section 26 are reproduced, high quality video dataequivalent to the I-Frame can be reproduced from the time of the videorecording start operation.

SECOND OPERATION EXAMPLE

In the first operation example described above, in the whole period fromthe video recording start operation to the video recording endoperation, display video data decoded in the multimedia processingsection 24 and equivalent to the I-Frame are recorded in the mainstorage section 26.

However, the storage of display video data is not limited thereto. Forexample, as shown in FIG. 7, only at the time of the video recordingstart, display video data decoded in the multimedia processing section24 and equivalent to the I-Frame are recorded in the main storagesection 26. And in the subsequent period till the video recording endoperation, received picture frames, that is, P-Frames, may be stored inthe main storage section 26.

By doing this, over the whole period from the video recording startoperation to the video recording end operation, in comparison to thecase in which display video data decoded in the multimedia processingsection 24 and equivalent to the I-Frame are recorded, the amount ofvideo data recorded in the main storage section 26 can be reducedsubstantially. As a result thereof, the storage capacity of the mainstorage section 26 can be used effectively, thereby prolonging therecording time of video data.

Second Embodiment

In a second embodiment of the present invention, at the time of a videorecording start operation carried out by a user, display video datareproduced by a decoding processing in the multimedia processing sectionare returned to the multimedia processing section, are re-encoded intoan I-Frame and are subsequently stored in the main storage section.Further, in a period from the time of the video recording startoperation to the time of a video recording end operation, display videodata reproduced by a decoding processing in the multimedia processingsection are returned to the multimedia processing section, arere-encoded into P-Frames and are stored in the main storage section.

FIG. 8 is a block diagram showing the functional organization of amobile terminal having an encoded data recording function according tothe second embodiment. Further, in the same figure, the identicalsections to FIG. 4 are marked with the identical symbols, and detaileddescriptions will be omitted.

The main control section 21B of a base band section 2B is provided witha displayed data recording control means 21 b and a re-encoding controlmeans 21 c as new control functions according to the present invention.

When a video recording start operation is carried out in theinput/output section 3 during communication, the displayed datarecording control means 21 b carries out main processing operations forstoring display video data reproduced by a decoding processing in themultimedia processing section 24 in the main storage section 26 for aperiod from the time of this video recording start operation to the timeof a video recording end operation.

When the displayed data recording control means 21 b stores the displayvideo data in the main storage section 26, the re-encoding control means21 c returns these display video data to be recorded to the multimediaprocessing section 24 and re-encodes them. And an I-Frame and P-Framesgenerated by this re-encoding are stored in the main storage section 26.

In such a composition, supposes that a user carries out a picturerecording start operation during TV phone communication. Then the maincontrol section 21B inputs display video data reproduced by means of adecoding processing in the multimedia processing section 24 into theencoding section in the multimedia processing section at the time ofthis video recording start operation. And an I-Frame obtained by are-encoding processing in this encoding section is stored in the mainstorage section 26 via the temporary storage section 25.

For a period till a user carries out a video recording end operation,each time display video data are reproduced by a decoding processing ofthe multimedia processing section 24, the display video data areinputted into the encoding section in the multimedia processing section24 and are re-encoded. And P-Frames generated by this re-encodingprocessing are stored sequentially in the main storage section 26 viathe temporary storage section 25.

FIG. 9 shows how the recording operation of video data using thisre-encoding processing is carried out.

Further, for a period from the video recording start operation to thevideo recording end operation, the main control section 21B stops theencoding processing of transmitted video data in the multimediaprocessing section 24 temporarily for re-encoding display video data.

As described above, according to the second embodiment, display videodata reproduced by a decoding processing in the multimedia processingsection 24 are re-encoded in the multimedia processing section 24 andare recorded in the main storage section 26. Therefore, the receivedvideo data can be recorded in a compressed condition. Accordingly, theamount of video data recorded in the main storage section 26 canreduced. As a result thereof, the storage capacity of the main storagesection 26 can be used more effectively, thereby prolonging therecording time of video data.

Moreover, the re-encoding processing of display video data is carriedout in the encoding section of the existing multimedia processingsection 24. Therefore, no encoder for re-encoding is newly required.Accordingly, a mobile terminal with larger-sized circuitry can beavoided.

Third Embodiment

In a third embodiment according to the present invention, when a usercarries out a video recording start operation during wireless TV phonecommunication using MPEG-4, display video data reproduced by a decodingprocessing in the multimedia processing section for a period from thetime of this picture recording operation to the time of a picturerecording end operation are held temporarily in the temporary storagesection. And, after the end of the TV phone communication, the displayvideo data held in the temporary storage section are read out, areinputted into the multimedia processing section and are re-encoded intoan I-Frame and a plurality of subsequent P-Frames. And the I-Frame andthe plurality of subsequent P-Frames obtained by means of thisre-encoding are stored in the main storage section.

FIG. 10 is a block diagram showing the functional organization of amobile terminal having an encoded data recording function according tothe second embodiment. Further, in the same figure, the identicalsections to FIG. 8 are marked with the identical symbols, and detaileddescriptions will be omitted.

The main control section 21C of a base band section 2 c is provided witha displayed data holding control means 21 d, a displayed data recordingcontrol means 21 e and a re-encoding control means 21 f as new controlfunctions according to the present invention.

When a user carries out a video recording start operation duringwireless TV phone communication, display video data reproduced by adecoding processing in the multimedia processing section 24 for a periodfrom the time of this video recording start operation to the time of avideo recording end operation are held temporarily in the temporarystorage section 25.

The displayed data recording control means 21 e monitors the end of thewireless TV phone communication. And the communication comes to end, thedisplay video data held in the temporary storage section 25 are read outand are inputted into the multimedia processing section 24. And anI-Frame and P-Frames obtained by this re-encoding processing in themultimedia processing section 24 are stored in the main storage section26.

The re-encoding control means 21 f controls the operation of themultimedia processing section 24 and re-encodes the display video dataread out from the temporary memory section 25.

Due to such a composition, when a video recording start operation iscarried out during communication, display video data decoded by themultimedia processing section 24 for a period from the time of thisvideo recording start operation to the time of a video recording endoperation are transferred to the temporary storage section 25 and areheld therein under control of the main control section 21C. Andsubsequently, when the end of communication is detected, the displayvideo data held in the temporary storage section 25 are read outsequentially in order of time under control of the main control section21C, are inputted into the encoding section of the multimedia processingsection 24 and are re-encoded into an I-Frame and subsequent P-Frames.And these re-encoded I-Frame and P-Frames are stored in the main storagesection 26 via the temporary storage section 25.

Therefore, according to the third embodiment, as in the secondembodiment, since display video data are re-encoded in the multimediaprocessing section 24 and are recorded in the main storage section 26,the received video data can be recorded in a compressed condition.Accordingly, the amount of video data recorded in the main storagesection 26 can reduced. As a result thereof, the storage capacity of themain storage section 26 can be used more effectively, thereby prolongingthe recording time of video data.

Further, in the third embodiment, the re-encoding processing is carriedout after the end of communication. Therefore, the re-encodingprocessing of video data to be recorded is permitted without stoppingthe encoding processing of transmitted data by the multimedia processingsection 24 temporarily. Moreover, the processing load of the maincontrol section 21C can be reduced, and therefore, no CPU or DSP havinga high processing capability is required.

Other Embodiments

In the second embodiment, when display video data are re-encoded in themultimedia processing section 24, the encoding processing of transmitteddata is stopped temporarily. However, the multimedia processing section24 has a sufficient signal processing capability, the encodingprocessing of transmitted picture data and the re-encoding processing ofdisplay video data may be carried out in time sharing.

As a result thereof, received video data can be recorded concurrentlywith video data being transmitted. Further, after the end ofcommunication, recorded received picture data can be reproducedinstantaneously.

Moreover, another video encoder for re-encoding display video data maybe provided in addition to the multimedia processing section 24 and there-encoding processing of display video data may be carried out by thispicture encoder. In this case, as a video encoder for re-encodingdisplay video data, an encoder permitting a higher-quality encoding suchas a MPEG-2 encoder is preferably used.

Further, as an encoding compression/extension scheme of video data,other schemes such as ITU-T H.263 or the like than MPEG-4 may beemployed, and with respect to data to be transmitted, still video dataand other data may be transmitted in addition to motion picture data.

Further, in the above-described embodiments, a case in which wireless TVphone communication is maintained between the mobile terminals MS1 andMS2 is described. However, in addition thereto, the present invention isalso applicable, for example, to a case in which a mobile terminal isconnected to a WWW server or the like on Internet via a network NW andinformation contained in a home page or the like is down-loaded fromthis server. Moreover, the present invention is also applicable to acase in which an electronic mail accompanied by motion picture data isreceived.

In the above-described embodiments, a mobile communication is describedas an example. However, the present invention can be applied to a radiotransmission system and the like between equipment using a shortdistance radio data transmission scheme represented by wireless LAN andBT (Bluetooth), and further it may be applied to a cable transmissionsystem such as a subscriber network using metallic cables or opticalfiber cables and a cable television broadcasting network.

Moreover, as an encoded data recording apparatus, a recorder or the likerecording video data or audio data received by a television tuner or acar radio is included in addition to communication terminals such as amobile terminal, a PDA and a personal computer.

Further, as an encoded data input means, means acquiring data from amobile recording medium such as a CD, a DVD or a memory card areincluded in addition to means into which encoded data are inputted froman external equipment by using a cable or a radio link.

And besides, it is to be understood that various changes in the kind andthe composition of terminals, the construction of a re-encoding meansand the like may be made without departing the summary of the presentinvention.

INDUSTRIAL APPLICABILITY

As described above in detail, in the present invention, when a datadisplay control means for receiving first data and second data,reproducing frame data of each frame based on these data and displayingthe frame data sequentially on the display is provided, at least thenewest frame data are held temporarily in the data holding means eachtime frame data are reproduced by this data display control means. Andwhen a recording instruction of the received data is inputted inreceiving the first data and the second data, reproduced frame data heldtemporarily in the data holding means are recorded in a recording mediumin the order corresponding to the time of having inputted the recordinginstruction.

Therefore, according to the present invention, there can be provided anencoded data recording apparatus and a mobile terminal capable ofrecording high-quality data immediately after having inputted arecording instruction by using reproduced display frame data even ifrecording is begun in receiving data.

1. A mobile terminal configured to record encoded data comprising anintra-coded frame generated based on original data having correlationson a time axis in an initial frame timing thereof and comprising aplurality of predictive-coded frames generated respectively in aplurality of frame timings subsequent to the initial frame timing, theintra-coded frame having an independent meaning alone and the pluralityof predictive-coded frame containing a difference between the originaldata of a current frame and original data of the preceding framerespectively, the mobile terminal comprising: means for receivingdigitized voice, video and other data in the mobile terminal via awireless network, the video data including the encoded data comprisingthe intra-coded frame and the plurality of predictive-coded frame; meansfor reproducing in the mobile terminal the original data for each frame,by performing decoding based on an intra-coded frame and a plurality ofpredictive-coded frames of the received encoded data; data holding meansfor temporarily holding in the mobile terminal the reproduced originaldata each time the original data is reproduced for each frame, and alsotemporarily holding the plurality of predictive-coded frames of thereceived encoded data obtained before decoding by the reproducing means;and recording control means for successively recording, in a recordingmedium of the mobile terminal, a part of the original data temporarilyheld in the data holding means when a recording start instruction isinput at a predetermined timing during a receiving period of the encodeddata, the part of the original data being data of a frame correspondingto a time when the recording start instruction is input and data offrames subsequent to the frame, wherein the recording control meansreads the original data corresponding to a first frame timing, whichcorresponds to the time when the recording start instruction is input,from the data holding means and stores the original data in therecording medium at the first frame timing, and records the plurality ofpredictive-coded frames in the received encoded data corresponding torespective frame timing subsequent to the first frame timing in therecording medium in the respective frame timings, and in a period fromwhen the recording start instruction is input to when video recordingand operation actually occurs, the predictive-coded frames are dataitems temporarily held by the data holding means and obtained beforedecoding by the reproducing means.
 2. A method for recording in a mobileterminal encoded data comprising an intra-coded frame generated based onoriginal data having correlations on a time axis in an initial frametiming thereof and comprising a plurality of predictive-coded framesgenerated respectively in a plurality of frame timings subsequent to theinitial frame timing, the intra-coded frame having an independentmeaning alone and the plurality of predictive-coded frame containing adifference between the original data of a current frame and originaldata of the preceding frame respectively, the mobile terminalcomprising: receiving digitized voice, video and other data in themobile terminal via a wireless network, the video data including theencoded data comprising the intra-coded frame and the plurality ofpredictive-coded frame; reproducing in the mobile terminal the originaldata for each frame, by performing decoding based on an intra-codedframe and a plurality of predictive-coded frames of the encoded datareceived in said receiving step; temporarily holding in the mobileterminal the reproduced original data each time the original data isreproduced for each frame; successively recording, in a recording mediumof the mobile terminal, a part of the temporarily held original data inthe data holding means when a recording start instruction is input at apredetermined timing during a receiving period of the encoded data, thepart of the original data being data of a frame corresponding to a timewhen the recording start instruction is input and data of framessubsequent to the frame, wherein the step of successively recordingcomprises: re-encoding data of the frame corresponding to the time whenthe recording start instruction is input and frames subsequent to theframe in the temporarily held original data into the intra-coded frameand the plurality of predictive-coded frames; recording the intra-codedframe and the plurality of predictive-coded frames; and wherein the stepof successively recording comprises: holding data of the framecorresponding to the time when the recording start instruction is inputand frames subsequent to the frame in the temporarily held original datatill the receiving period of the encoded data comes to an end;re-encoding the original data into the intra-coded frame and theplurality of predictive-coded frames after the receiving period of theencoded data comes to an end; and recording the intra-coded frame andthe plurality of predictive-coded frames.
 3. A mobile terminalconfigured to record encoded data comprising an intra-coded framegenerated based on original data having correlations on a time axis inan initial frame timing thereof and comprising a plurality ofpredictive-coded frames generated respectively in a plurality of frametimings subsequent to the initial frame timing, the intra-coded framehaving an independent meaning alone and the plurality ofpredictive-coded frame containing a difference between the original dataof a current frame and original data of the preceding framerespectively, the mobile terminal comprising: a receiver configured toreceive digitized voice, video and other data in the mobile terminal viaa wireless network, the video data including the encoded data comprisingthe intra-coded frame and the plurality of predictive-coded frame; areproducing processor configured to reproduce in the mobile terminal theoriginal data for each frame, by performing decoding based on anintra-coded frame and a plurality of predictive-coded frames of thereceived encoded data; data storage device configured to temporarilyhold in the mobile terminal the reproduced original data each time theoriginal data is reproduced for each frame; and recording controlprocessor configured to successively record, in a recording medium ofthe mobile terminal, a part of the original data temporarily held in thedata storage device when a recording start instruction is input at apredetermined timing during a receiving period of the encoded data, thepart of the original data being data of a frame corresponding to a timewhen the recording start instruction is input and data of framessubsequent to the frame, wherein the recording control processor isconfigured to read the original data corresponding to a first frametiming, which corresponds to the time when the recording startinstruction is input, from the data storage device and to store theoriginal data in the recording medium at the first frame timing, and torecord the plurality of predictive-coded frame in the received encodeddata corresponding to respective frame subsequent to the first frametiming in the recording medium in the respective frame timings, andwherein the recording control processor comprises: a re-encoderconfigured to re-encode data of the frame corresponding to the time whenthe recording start instruction is input and frames subsequent to theframe in the original data temporarily held in the data storage deviceinto the intra-coded frame and the plurality of predictive-coded frames;and recording processor configured to record the intra-coded frame andthe plurality of predictive-coded frames in the recording medium; andwherein the step of successively recording comprises: holding data ofthe frame corresponding to the time when the recording start instructionis input and frames subsequent to the frame in the temporarily heldoriginal data till the receiving period of the encoded data comes to anend; re-encoding the original data into the intra-coded frame and theplurality of predictive-coded frames after the receiving period of theencoded data comes to an end; and recording the intra-coded frame andthe plurality of predictive-coded frames.
 4. A mobile terminalconfigured to record encoded data comprising an intra-coded framegenerated based on original data having correlations on a time axis inan initial frame timing thereof and comprising a plurality ofpredictive-coded frames generated respectively in a plurality of frametimings subsequent to the initial frame timing, the intra-coded framehaving an independent meaning alone and the plurality ofpredictive-coded frame containing a difference between the original dataof a current frame and original data of the preceding framerespectively, the mobile terminal comprising: a receiver configured toreceive digitized voice, video and other data in the mobile terminal viaa wireless network, the video data including the encoded data comprisingthe intra-coded frame and the plurality of predictive-coded frame; areproducing processor configured to reproduce in the mobile terminal theoriginal data for each frame, by performing decoding based on anintra-coded frame and a plurality of predictive-coded frames of thereceived encoded data; data storage device configured to temporarilyhold in the mobile terminal the reproduced original data each time theoriginal data is reproduced for each frame; and recording controlprocessor configured to successively recording, in a recording medium ofthe mobile terminal, a part of the original data temporarily held in thedata storage device when a recording start instruction is input at apredetermined timing during a receiving period of the encoded data, thepart of the original data being data of a frame corresponding to a timewhen the recording start instruction is input and data of framessubsequent to the frame, wherein the recording control processor isconfigured to read the original data corresponding to a first frametiming, which corresponds to the time when the recording startinstruction is input, from the data storage device and to store theoriginal data in the recording medium at the first frame timing, and torecord the plurality of predictive-coded frame in the received encodeddata corresponding to respective frame timings subsequent to the firstframe timing in the recording medium in the respective frame timings,and wherein the recording control processor comprises: a frame storagedevice configured to hold data of the frame corresponding to the timewhen the recording start instruction is input and frames subsequent tothe frame in the original data temporarily held in the data storagedevice till the receiving period of the encoded data comes to an end; are-encoding processor configured to re-encoded the original data held inthe data storage device into the intra-coded frame and the plurality ofpredictive-coded frames after the receiving period of the encoded datacomes to an end; and a recording processor configured to record theintra-coded and the plurality of predictive-coded frames in therecording medium.